About a half-million people call an estimated 2,000 poor and isolated "colonias" home. The sparse communities dot the landscape of south Texas, along the more-than-1,000 miles the state's border shares with Mexico.

A staggering 100,000 of the residents -- mostly all U.S. citizens -- are children.

Maria Castro, 12, is among them and lives in a small house that her father built with her mother, nine of her sisters and brothers, and two cousins.

Outwardly, Maria seems like most other American girls her age. She wants to look her best at school, rides a yellow school bus to get there, and enjoys playing flute in the school band.

"My dream is to be someone in life. That's all," she said. "I actually want a better life than we have right now."

At school, Maria finds refuge from her life back at home in las colonias, marked by dirt roads and cut off from the rest of society, a kind of barren no-man's land. There is sometimes no electricity or running water, no sewers, drainage or streetlights, and no garbage collection. Trash in las colonias is burned. Most are without cell phones and computers.

Alma Castro, Maria's mother, said she has lived there for 21 years and survival is a matter of daily hard work. Alma Castro is up at 5 a.m. each morning to harvest the fruits and vegetables that help feed the rest of the nation. As a single mother, she earns $7 an hour.

It's a work ethic Alma Castro wants her children to value so she takes them to the fields, not because she wants them to work there, but because she wants them to aspire for more, she said. In tears, she said she will keep going "until I raise my last child."

Poverty takes another toll too -- a physical one. Alma said she has diabetes, high cholesterol, asthma and arthritis. One third of residents have no insurance and though they often qualify for Medicad, they are so isolated that tapping those resources is a challenge. If residents get sick, they simply tough it out, even when afflicted rare diseases seen here, including tuberculosis and even cholera.

Another colonias resident, 8-year-old Evelyn, said she often doesn't get enough to eat.

Generation after generation continue to put down stakes here, although they see themselves as "los olvidados" -- the forgotten ones. They are largely ignored by county and state officials.

Ann Cass runs a non-profit organization, Proyecto Azteca, which is committed to building better homes in las colonias. Most of the las colonias homes are built crudely from scrap metal and whatever materials are lying around. Cass insists that more should be done for this hidden people.

"Don't let this people remain hidden any longer. They're paying taxes. They have right to decent housing and opportunities," she said.

Born and raised in las colonias, Juanita Valdez-Cox, the executive director of LUPE, also understands and knows all too well how hard it is.

"I think they will always be hidden. They're so far off of the main highways," she said. "But we need to make sure that they're not forgotten, and they can't be forgotten."

But even in this neglected, hidden corner of America, dreams die hard. Twelve-year-old Maria has aspirations for a better life.

"I'm going to be a surgeon, so I can help people that they need life, that they need the surgery. They can't afford it," she said. "I want to be a person that can do it to them for free."